The Environment
A forward surgical team operates from a deployable field facility providing trauma surgery and critical care in a contested operational area. The digital infrastructure is tactical in design and ruggedized for field conditions: a satellite communications terminal providing a narrow-bandwidth uplink that operates only during scheduled windows and is subject to denial by adversary electronic warfare; ruggedized laptops running a hardened OS; a locally hosted electronic medical records (EMR) system on a hardened mini-server; portable medical devices connected to the local network via wired LAN; and a classified communications terminal on a physically separate network. Power is supplied by a tactical generator with variable availability.
The operational requirement was absolute: Frostbow must operate with zero dependency on external connectivity. All processing, detection, and response must function entirely on locally hosted infrastructure during extended periods of complete network isolation. A single signals technician was available for deployment and ongoing support.
Frostbow Deployment
Frostbow was deployed from a pre-configured package by the signals technician in under two weeks. Lightweight collector agents were installed on all ruggedized laptops and the EMR server. Medical devices were monitored passively via port mirroring on the local managed switch — no agent installation on clinical hardware. The classified terminal network was physically segregated and out of scope. All detection and response functions operated entirely offline; log synchronization to higher headquarters was configured to batch automatically during available communications windows.
The Scenario: Dormant Implant Activation Targeting Medical Records
During an extended communications blackout caused by adversary electronic warfare, a dormant implant on the EMR server — introduced via a USB drive during a personnel rotation weeks earlier — was remotely activated. The implant began exfiltrating patient records and unit personnel data, writing small encrypted packets to a hidden directory for later retrieval. The implant ran under a spoofed service name closely resembling a legitimate system process.
How Frostbow Responded
The implant, dormant since introduction, had shown no behavioral indicators during Frostbow’s observation period. Upon activation, it began reading from patient record tables at a rate and pattern inconsistent with normal EMR application behavior — Frostbow had built a detailed baseline of the EMR server’s database read patterns, including query rates, file access sequences, and the expected process tree for normal operation.
The divergence was detected within 90 seconds. The implant process, despite its spoofed service name, was spawned from an unusual parent process that did not match Frostbow’s established concept of NormalEMRServerBehavior. Write activity to the hidden staging directory triggered an additional concept: StagingDirectoryCreation, which Frostbow had learned preceded exfiltration in 71% of observed cases across the deployment network.
With no analyst present and no external connectivity, Frostbow acted autonomously: it terminated the implant process, quarantined the staging directory, and locked the compromised service account. Medical operations on the EMR system were unaffected — patient care continued without interruption. A full incident report was stored locally and transmitted automatically when the next communications window opened. The signals technician was notified via the local dashboard and was able to confirm quarantine and preserve forensic evidence.
Key Deployment Characteristics
- Fully air-gapped, offline operation with zero external connectivity dependency
- Single-technician deployment from pre-configured package
- Autonomous detection and response with no analyst present
- Incident reporting batched for transmission during available connectivity windows
- Passive network tap monitoring of medical devices — no agent installation on clinical hardware
- Minimal footprint architecture suited to austere, power-constrained environments